 It is possible to become a painter, a sculptor, or a musician by study, but not a dramatic poet; a man is so either at once or never, as he is blonde or brown, and cannot help it. Preface to Le Père Prodigue (1859), in Théatre complet de Al. Dumas fils (Paris: Michel Lévy Frères, 1868-98) vol. 3, p. 199; translation by E. P. Evans from The Atlantic Monthly, May 1890, pp. 584-5.

 ... an author never does more damage to his readers than when he hides a difficulty. in the preface of Deux mémoires d'Analyse pure, October 8, 1831, edited by Jules Tannery (1908). Manuscrits de Évariste Galois. Gauthier-Villars. p. 27.